Known are connections for conduits having components comprising two activation surfaces. These activation surfaces are pressed towards each other for building up the connection. Conical or wedge-like surfaces of the connection transform an axial movement of the components pressed towards each other into a plastic deformation of at least one component of the connection. Such plastic deformation might be used for radially compressing the components of the connection for building up a fixed and sealed connection.
European Patent No. EP 1 055 488 B1, corresponding to U.S. Pat. No. 6,415,641 discloses a clamping fitting with two parts, i.e. a supporting sleeve and a clamping sleeve. For connecting ends of conduits with each other one end of a conduit is widened and houses the clamping fitting. The widening process represents an additional costly step. A device axially presses the clamping sleeve into a final position, wherein the clamping sleeve abuts the clamping fitting. Another clamping technique uses a clamping ring and a squeezing ring passed over a conduit. A supporting sleeve is introduced into the conduit. The device axially presses the clamping ring versus the squeezing ring until a stop element built from the supporting sleeve is reached. For such modification a widening of the conduit is not necessary.
Another connection for conduits is disclosed on the website www.schell-armaturen.de/deutsch/downloads/pex_bosch.pdf, wherein the connection is used for sanitary facilities or heating devices. The conduits used might be made of high molecular polyethylene. The conduits are manufactured without any flashes or burrs. Furthermore, for preparing the connection each conduit is cut to the desired length with a cut strictly perpendicular to the longitudinal axis of the conduit. A sleeve is passed over the conduit. A special widening tool is inserted into the opening of the conduit. After the use of the widening tool a fitting is inserted into the widened open cross-section of the conduit. An end position of the fitting in the widened conduit is given for the front surface of the conduit abutting a stop element of the fitting. A pressing tool with an electric drive unit presses the sleeve axially versus the stop element for finishing the clamping or crimping process.
A further embodiment for a sealed pressure connection made of metal might be taken from website www.mapress.de/geberit, wherein the disclosed product is distributed under the trademark MapressMAM. The connection is used for industrial applications under rough conditions, i.e. high pressures, changes of the pressure, rough temperature conditions and corrugation. For building an undetachable connection a ring made of stainless steel is passed over the conical outer end region of a fitting. Conduit, fitting and ring are connected by axially pressing these components against each other. The connection might be built without any additional sealing elements. The fitting might provide five defined pressure zones for producing a permanently sealed connection.
German Patent No. DE 44 46 503 C1 suggests to use a pressing tool activated by a pressure medium for axially moving the components of a connection.
The application of an axial movement might be simplified by use of a manually operated tool. German “Gebrauchsmuster” No. DE 93 07 957 U1 discloses pressure pliers having hand levers pivoted around a pivoting bolt. The end regions of the hand levers opposite to the end regions gripped by the hand of the user are pivotably linked with base jaw elements. The base jaw elements comprise grooves directed transverse to the pressing direction. Pressure jaws comprise D-shaped sliding blocks engaging the grooves. The pressure jaws might be U-shaped building an opening, wherein the width of the opening approximately correlates with the diameter of the ends of the conduits, a sleeve or a sliding sleeve. From the outside the pressing jaws grip activation surfaces built by a collar of the sleeve and an outer front surface of the sliding sleeve. With a pivoting movement of the hand levers versus each other the base jaw element and the pressing jaws are pivoted versus each other. Such pivoting movement correlates with a relative movement of the collar contacting one of the pressing jaws and the sliding sleeve contacting the other pressing jaw. Due to the pivotable link of the end regions of the hand levers with the base jaw elements, during the axial movement the pressing jaws are automatically held in a parallel orientation for providing a uniform contact between the pressing jaws and the activation surfaces. DE 28 51 282 discloses similar pressing jaws.
Additional manually applied pressing pliers are known from German Patent Application No. DE 36 17 529 A1.
German “Gebrauchsmuster” No. DE 93 07 957 U1 discloses pressing pliers having hand levers pivotably linked in X-shape by a bolt. The end regions of the hand lever facing the work piece are pivotably linked with base bodies having U-shaped nests for sleeves. These sleeves are pressed against each other in axial direction with a pivoting movement of the hand levers versus each other. The U-shaped nests are releasably fixed at the base bodies via T-slots. The U-shaped nests are held in parallel orientation during the pressing movements. This is done by linking the base body both with one end region of a first hand lever and a spring pressing the base body against a pin fixed at the second hand lever. German Patents DE 28 51 282 C2, corresponding to U.S. Pat. No. 4,257,135 and DE 36 17 529 C2 disclose embodiments of pressing tools basing on the same mechanism for keeping the nests in parallel orientation.
German “Gebrauchsmuster” DE 20 2004 008 603 U1 discloses pliers for bringing retaining rings according to German norm DIN 471/472 under tension and releasing these retaining rings. For these pliers the two hand levers in closed state build in a rough approximation the contour of a H wherein the transverse leg of the H is shifted versus the upper end region of the two longitudinal legs and the two hand levers are pivotably linked in the middle of the transverse leg. The end regions of the hand levers facing the work piece are pivotably linked with the end regions of jaws. The jaws cross each other building an X with a joint at the crossing point. For opened hand levers the nests of the jaws have a minimal distance with parallel orientation. However, with a closing movement of the hand levers the nests separate from each other with an increasing angle built by the two nests.
German Patent No. DE 196 21 877 C2 discloses pressing pliers driven by hand with a pistol-like design for pressing sleeves upon tubes or fittings. The trigger of the pistol builds a movable hand lever, whereas the handle of the pistol builds a fixed hand lever. A front nest is fixed at the end of the barrel of the pistol. Another nest is guided for a movement along the barrel of the pistol. A repeated closing movement of the hand levers is transferred by an eccentric drive mechanism drive and a ratchet link to a pressing movement of the movable nest versus the fixed front nest.
German Patent Application No. DE 10 2006 022 999 A1 discloses pliers wherein multi-part hand levers are linked with each other building an X. A supporting body building U-shaped nests is linked with the end regions of the hand levers facing the work piece. The U-shaped nests are held in parallel orientation during a spreading movement with a closing movement of the hand levers. For that purpose the supporting bodies each comprise pins having an orientation transverse to the spreading axis. The pins each have a bore parallel to the spreading axis. A guiding rod penetrates the aforementioned bores of the two supporting bodies.
European Patent No. EP 0 598 173 B1 discloses a pressing tool with an external drive built by a drilling machine. By means of a spindle drive the driving movement of the drilling machine is transferred to a translational relative movement of two plates. Each of the plates at the circumference comprises a plurality of U-shaped nests. In order to use the pressing tool for work pieces or tubes having different dimensions the plurality of nests of the plates have different opening sizes. It is possible to rotate the plates around the pressing axis for bringing different nests into an operating position.
European Patent No. EP 1 055 488 B1, corresponding to U.S. Pat. No. 6,415,641 discloses a pistol-like pressing tool with an electro-hydraulic drive. A hydraulic pressure acting upon a cradle moves a nest having a translational degree of freedom versus a fixed nest for pressing a work piece.
Japanese Patent Application No. JP 2000117655 A discloses crimping pliers with a L-shaped hand lever. Another hand lever is pivotably linked with the shorter transverse leg of the L. A nest for a work piece is fixed at the L-shaped hand lever. Another nest is guided by the transverse leg of the L in pressing direction. A curved front surface of the pivotable hand lever comprises a toothing meshing with a linear toothing of the movable nest such that a pivoting movement of the hand levers correlates with a translatory relative movement of the two nests.